Invalid postback or callback argument. Event validation is enabled using

Hello,

I've tried to add options to dropdown list with choice controller in nintex form using jquery, but when I tried to submit the form I've got this exception:

Invalid postback or callback argument. Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page. For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them. If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.

I understand what the problem is, but I couldn't find how to solve this, I mean how to disable Event validation, or how to register the new added options in the dropdown.

Omar Taha‌Remove the white spaces for all the drop down lists within Nintex form. I had exactly same issue and found that Drop down fields has white spaces. I removed all drop down lists within Nintex form and it worked.